Autogas, also LPG (liquified petroleum gas) is a liquid gas that can be used in cars as a fuel.
Due to the current discussions about global warming, CO2 emissions and rising fuel prices, fossil fuels are becoming more and more popular. The autogas system is most commonly installed in passenger cars, here in germany.
autogas became "famous" in italy already in the 70s. It was immediately accepted there and even today a lot of vehicles there run on LPG. In istanbul, autogas has also become established, and all cabs there run on liquefied petroleum gas. In the 80’s it was also known in austria, but quickly forgotten, because autogas was highly taxed there. Today, however, all regular-service buses in Austria run on the propane/butane mixture.
The conversion to LPG is possible in any car with a gasoline engine, regardless of power and number of cylinders. Older vehicles (before year 98) are usually equipped with a semi-automatic system that uses a common injection system, as the engine control units do not support any other type of control. Prices vary between 1400 and 3500€.
Special autogas tanks, mostly steel tanks, are used as fuel tanks for autogas vehicles. The tanks can be installed inside the vehicle, z.B. In the spare wheel well in the trunk, or mounted as underfloor tanks. Autogas is used under relatively low pressures of approx. 8 bar stored in liquid form in the autogas tank (for comparison: natural gas approx. 200 bar). This means that even relatively small autogas tanks can cover long distances. Depending on the type of vehicle and the way it is driven, 400 to 600 kilometers can be easily covered on a single tank of gas.
Cylinder tank in the trunk
Refueling is exactly the same as with a normal tank. The nozzle is mounted next to the petrol nozzle.
From the basic structure, an evaporator pressure regulator converts the autogas, which comes from the tank in liquid form, into a gaseous state. At the same time, the gas is reduced to the pressure required for combustion. Modern autogas systems are similar to gasoline injection systems and record a large number of engine parameters to control the mixture formation. the system feeds the gas with overpressure in separate lines directly to the intake valves of the individual cylinders. A microprocessor regulates the autogas drive and thus ensures low-pollutant and efficiency-optimized combustion in the engine.
The special properties of liquefied petroleum gas allow both gaseous and liquid autogas to be injected. In contrast to gas injection systems, liquid injection systems do not have an evaporator. In these systems, a pump installed in the autogas tank with a pressure regulator ensures a constant pressure in front of the injectors.
The vehicle can run on gas only (monovalent) or automatically or manually switch between gas and petrol (bivalent). the bivalent drive offers such a plus point, namely a significantly higher range of up to 1000km.